It took Freddie Mercury seven years to write “Bohemian Rhapsody,” the 1975 masterpiece that would define his career. He’s said to have started the lyrics while studying at London’s Ealing Art College in 1968, a couple years before forming the band Queen. All he had initially was the opening line: “Mama, just killed a man.” It sounded like something a lonesome gunfighter would say, so Mercury dubbed it “The Cowboy Song.”

By the time he got around to recording it with Queen for their fourth album, 1975’s A Night at the Opera, Mercury had a clear vision of where the song was headed. There would be a soft balladic intro, followed by a lush operatic section with lyrics about Galileo Galilei, “the father of modern astronomy,” and lots of other stuff that would leave most teen rock fans scratching their heads. After that, a muscular hard-rock part, then more piano balladry for the tearjerker ending. Much to the record company’s chagrin, the song would have to be six minutes long.

In a clip from the new Queen biopic Bohemian Rhapsody, we see Mercury, played by Rami Malek, in full-on taskmaster mode, pushing drummer Roger Taylor (Ben Hardy) to sing the word “Galileo” higher and higher and higher, until it seems the poor guy’s vocals might scrape one of those celestial bodies Galileo spent his life studying.

In real life, Mercury wasn’t being some arbitrary diva. He was a perfectionist, and “Bohemian Rhapsody,” was to be a grand statement—a song that would offer a rare glimpse into his soul while exploring the idea of what a rock song could be.

Thanks to his bandmates, who helped Mercury and producer Roy Thomas Barker pile on 180 overdubs, Mercury got his wish. Despite—or perhaps because of—its supreme weirdness, “Bohemian Rhapsody” topped the U.K. charts in 1975 and went Top 10 in America.

Queen would score many more hits in the next decade, including the funk-rock classic “Another One Bites the Dust” and retro rockabilly rave-up “Crazy Little Thing Called Love,” but “Bohemian Rhapsody” is the one everyone thinks of first. It hints at Mercury’s hidden inner-self and showcases everything that made Queen one of the strangest, most wonderfully bombastic rock bands of all time.

“Bohemian Rhapsody” represents a crossroads in Mercury’s life. While it points the way forward to greater fame and fortune, it also connects back to the singer’s unlikely road to stardom. Mercury was born Farrokh Bulsara on September 5, 1946, in Zanzibar, then a British holding off the eastern coast of Africa. As the son of a well-to-do High Court cashier for the British government, Freddie was exposed to lots of opera around the house. He also had the privilege of studying music at St. Peter’s, the fancy Indian boarding school where he formed his first rock band.

“Bohemian Rhapsody” would offer a rare glimpse into Freddie Mercury’s soul while exploring the idea of what a rock song could be.

Amid upheavals in Zanzibar, Mercury moved with his family to London in 1964. Six years later, the worldly art-school graduate formed Queen with two other educated lads—Taylor and guitarist Brian May—who didn’t try to hide their intellect or social status. They toyed with calling the band The Rich Kids or Grand Dance before Mercury suggested Queen. He was obviously aware of the gay connotation, but as Freddie told people at the time, he wanted a name to match the regal sound he and his bandmates were singularly equipped to create.

For all their musical chops and creativity—not to mention Freddie’s mighty tenor vocals—Queen didn’t make much of an impression with their first two albums, 1973’s Queen and 1974’s Queen II. Their breakthrough came with their third LP, 1974’s Sheer Heart Attack, which featured the single “Killer Queen.”

The track revolves around Mercury’s strolling vaudevillian piano and sing-songy lyrics about a woman who’s “dynamite with a laser beam / guaranteed to blow your mind, anytime.” Rock history is filled with songs about treacherous women, but “Killer Queen” is something different. Mercury claimed it was inspired by a high-class prostitute, and yet he never leers at or degrades his subject. If anything, he’s awed by this woman’s style and dedication to image:

She keeps Moet et Chandon
In her pretty cabinet
‘Let them eat cake’ she says
Just like Marie Antoinette

“Killer Queen” is stately and catchy and cheeky at the same time. In both the U.K. and U.S., it was Queen’s biggest hit prior to “Bohemian Rhapsody.” Fans who bought Sheer Heart Attack to hear “Killer Queen” would’ve also been smacked on the forehead by tunes like “Stone Cold Crazy,” a speedy riff-rock beast that presaged speed and thrash metal. The dichotomy heard in “Bohemian Rhapsody” was there from the beginning. Mercury may have vamped around in nail polish and unitards, but Queen could rock hard enough to satisfy any Led Zeppelin fan.

Both sides came together wondrously on “Bohemian Rhapsody,” a song with lyrics as confounding as the music. Some suggest the prog-pop epic was Mercury’s way of coming out as gay or bisexual. The outwardly flamboyant singer was famously guarded about his personal life, and following his death from AIDS in 1991, his former bandmates said they never really discussed his sexuality.

Mercury may have vamped around in nail polish and unitards, but Queen could rock hard enough to satisfy any Led Zeppelin fan.

The confessional interpretation is plausible and compelling but hardly essential if you want to connect with the emotion of “Bohemian Rhapsody.” Take away that stuff, and we’re still left with a fantastic song about a man overcome by demons (“Beelzebub has a devil put aside for me, for me, for meeeeee!”) and the fear he’s thrown his life away.

Mercury famously said the lyrics were “just about relationships,” with “a bit of nonsense in the middle.” He was referring, of course, to the famed operatic section, in which he places Galileo alongside Figaro, the title character of the 18th century French play The Barber of Seville (and subsequent operas by Mozart, Paisiello, and Rossini), and Scaramouche, a type of clownish figure found in Italian commedia dell'arte plays.

Whatever the exact meaning of these high-brow allusions, the operatic segment adds a fantastical counterpoint to the real-world suffering described earlier in the song. Mercury quells his pain with pomp and theatricality, a bit like he does on “Somebody to Love,” the lead single off Queen’s follow-up to A Night at the Opera, 1976’s A Day at the Races. The stakes aren’t quite as high as they are in “Bohemian Rhapsody”—Mercury doesn’t confess to shooting anyone—but the man we meet in “Somebody to Love” clearly needs a hug:

Each morning I get up I die a little
Can barely stand on my feet
(Take a look at yourself in the mirror and cry)
Take a look in the mirror and cry
Lord what you’re doing to me

Reportedly inspired by Aretha Franklin, one of Mercury’s favorite singers, “Somebody to Love” strikes a more triumphant tone than “Bohemian Rhapsody.” In the third verse, when he sings, “I ain’t gonna face no defeat,” Mercury foreshadows the electrical shock of empowerment he’d send coursing through 1977’s “We Are the Champions.” For a guy with little interest in sports, Mercury sure knew how to write a stadium anthem.

The bravado he summoned for “We Are the Champions” defined his public persona. For all the tortured love songs he sang, Mercury’s enduring image is that of a strutting rock god with a powerhouse voice who’ll demolish any audience. On “We Will Rock You,” Queen’s other immortal 1977 jock jam, Mercury sings the hook with enough ferocity to completely flip the meaning of May’s lyrics.

As per a 2012 ESPN story, the guitarist intended the song to be about “the futility of man.“ The phrase “we will rock you” actually comes from a Czech lullaby. Mercury makes it a rallying call, a threat to any foe. It’s undoubtedly shaking the bleachers at a sporting event somewhere in the world this very moment.

Whatever he may have been dealing with behind closed doors, Mercury was determined to put on a show. Queen’s finest moment came on July 13, 1985, when the band played Wembley Stadium as part of Live Aid. Cue it up on YouTube and prepare to be astonished. The set kicks off with “Bohemian Rhapsody,” and the roar that ripples through the crowd as Freddie strikes the opening piano chords sends shivers down the spine.

Queen didn’t even play the whole thing before segueing into “Radio Gaga,” the 1984 single that would inspire Stefani Joanne Angelina Germanotta to call herself Lady Gaga, and they didn’t have to. Three minutes of “Bohemian Rhapsody” is more than enough to bring 72,000 people to their knees.

In terms of massive pop-cultural moments, “Live Aid” wasn’t the last hurrah for “Bohemian Rhapsody.” The song went on to score the famous headbanging scene in 1992’s Wayne’s World, a movie about two Midwestern metal dudes chasing their showbiz dreams in the face of naysayers and corporate goons. Mercury’s magnum opus was the perfect choice for the scene. Even with his supernatural talent and larger-than-life image, Freddie was an underdog outsider not entirely unlike Wayne and Garth.

The best Queen songs are about being your own person and having the audacity to live freely in a gray and judgmental world. At least that’s the message Freddie couldn’t help but communicate every time he grabbed a mic stand and peacocked across the stage making grand theatrical gestures. If Queen were more than the sum of its incredible parts, Mercury somehow became more than that. It’s cosmic next-level rock ‘n’ roll math that not even Galileo could explain.